Authorities in New Zealand ‘unlawfully’ wiretapped on Kim Dotcom, the founder of Megaupload, who faces extradition to the United States on copyright charges, it has emerged.

New Zealand’s Prime Minister John Key opened an investigation into the incident, which he revealed on Monday.

Kim Dotcom, a flamboyant German national, faces charges of internet piracy and breaking copyright laws. The alleged copyright breaches are said to have cost the music and film industries more than $500 million.